The victory moved Wanneroo from 10th to ninth place, on equal points with four teams above it, including the fifth placed Willetton.
At Sutherlands Park, the Roos had little trouble accounting for the hosts, bowling them for a modest 123 and losing just two wickets in chasing down the total in 28 overs.
Wanneroo’s Jake Fawcett took 3-22 as the visitors’ best bowler, including the scalp of former WA batsman Luke Pomersbach, who top scored for Gosnells with 38.
The Roos’ Matthew Spoors (55) and Rob Richards (54*) combined for a 76-run partnership to do the majority of the damage.
Two-day action returns in the lead-up to finals this weekend with Wanneroo facing South Perth.